Certain bi(spiro(2h-1-benzopyran-2 2&#39;-benzothiazoline)) compounds

ABSTRACT

PHOTOCHROMIC COMPOUNDS WHICH ARE USEFUL TO CHANGE COLOR UPON EXPOSURE TO RADIATION, COMPRISING DI-SPIROPYRANS OF THE FORMULA   5,6-(-D(-X)-),5&#39;&#39;,6&#39;&#39;-(-D&#39;&#39;(-Y)-),1&#34;,2&#34;-DI(R-)-1&#34;,2&#34;,3&#34;,4&#34;,5&#34;   6&#34;-HEXAHYDRODISPIRO(2H-PYRAN-2,3&#34;-PYRADAZINE(E)-2&#39;&#39;,6&#34;-   2H-PYRAN)   IN WHICH, E REPRESENTS A HETEROCYCLIC SYSTEM HAVING WEAK OR ZERO ABSORPTION IN THE VISIBLE SPECTRUM, D AND D&#39;&#39; REPRESENT MONO OR POLYCYCLIC AROMATIC OR HETEROCYCLIC SYSTEMS CAPABLE OF COMBINING WITH SUBSTITUENTS X AND Y, AND X AND Y ARE CHOSEN FROM H-, CH3-, C2H5-, C6H5-, CHO-,CH3CO-, CH3O-, NO2-, CN-, CH3COO-, CF3-AND HALOGENS, AND R REPRESENTS AROMATIC, ALIPHATIC, OR ARYL-ALIPHATIC RADICALS, AND METHODS OF PRODUCING THE COMPOUNDS AND DEVICES USING THE COMPOUNDS.

United States Patent 3,631,172 CERTAIN BI[SPIRO(2H-1-BENZOPYRAN-2,2'- BENZUTHIAZOLINEH COMPOUNDS Rene Lucien Gautron, Sceaux, Seine, France, assignor to Compagnie de Saint-Gobain, Neuilly-sur-Seine, France No Drawing. Filed June 7, 1966, Ser. No. 555,676 Claims priority, applicationFrance, June 11, 1965,

int. or. (5074 91/24 US. Cl. 260--304 4 Claims ABSTRACT OF THE DISCLOSURE Photochromic compounds which are useful to change color upon exposure to radiation, comprising di-spiropyrans of the formula in which, E represents a heterocyclic system having weak or zero absorption in the visible spectrum, D and D represent mono or polycyclic aromatic or heterocyclic systems capable of combining with substituents X and Y, and X and Y are chosen from H, CH C H C H CHO-, CH CO, CH O-, NO CN, CH COO-, CF and halogens, and R represents aromatic, aliphatic, or aryl-aliphatic radicals, and methods of producing the compounds and devices using the compounds.

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It is know that the absorption bands in the visible spectrum of these spiropyran compounds in their colored form are somewhat narrow and only include part of the visible spectrum; this involves the necessity at times of associating several different photochromic compounds having complementary absorption ranges in order to achieve a wider absorption range in the assembly.

The present invention is based on the discovery by applicant that one can increase the absorption range of a spiropyran compound in its colored form by introducing two spiropyran groups in a single molecule of a photochromic substance.

Accordingly, this invention has for one object dispiropyran compounds, that is compounds containing the spiropyran function twice in the same molecule.

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The invention has for further objects a method of producing such compounds and methods of using them.

The photochromic dispiropyran compounds characterizing this invention have the following general formula:

in which: E represents a nitrogenous heterocyclic system having weak or zero absorption in the visible spectrum; D and D represent mono or polycyclic aromatic or heterocyclic systems capable of combining with substituents X and Y; and X and Y are chosen from the following substituents: H, CH C H C H CHO, CH CO, CH O-, NO CN, CH COO, CF and halogens.

Among the nitrogenous heterocyclic systems E in this formula may be mentioned, but without limitation, the following:

s s s s O i i N \N R3 R3 1 13 II13 R1 R2 R1 R: R1 R2 R1 R2 R3 is l. l.

CH3 CH3 R R and R representing aromatic, aliphatic or arylaliphatic radicals which may be identical or different.

As suitable cyclic systems D and D may be mentioned, but without limitation, divalent monor or polynuclear aromatic or heterocyclic systems such as residues of phenyl, diphenyl, naphthyl, anthracyl, phenanthryl and pyridyl which form the group consisting of orthophenylene, orthodiphenylene, orthonaphthylene, orthoanthacylen, orthophenanthrylene and orthopyridylene radicals. These cyclic systems may include the substituents X and Y as indicated above.

A process of synthesizing the novel dispiropyran compounds according to this invention comprises reacting a heterocyclic or an aromatic monohydroxymonoaldehyde, such as, for example, a substituted derivative of salicyl aldehyde or hydroxynapthaldehyde, with a nitrogenous dimethylene compound having the structure E, defined above, and having two methylene groups ortho to the two atoms of nitrogen (that is in position 2), or alternatively with a salt of such a nitrogenous dimethylene compound.

Thus in the case in which a substituted salicylaldehyde is used, the synthesis may be represented as follows:

CH CH0 This condensation is effected very simply by bringing into contact the two reactants in stoichiometric ratio, that is two molecules of the hydroxy aldehyde to one molecule of the dimethylene compound.

The condensation is preferably carried out in a solvent for the two reactants, as for example alcohol, benzene,

tetrahydrofuran, etc.

Heat in general accelerates the reaction, but it is not essential. The separation of the dispiropyran compound of the invention from the reaction mixture is efiected in any suitable way, for example, by precipitation or atmospheric or vacuum evaporation of the solvent.

Applicant has discovered that one obtains particularly useful photochromic dispiropyran compounds starting with the diiodide of bis(ethyl-2, methyl-3, benzothiazolium)- having the formula:

I Gain, 5g, I cut f x-c.1115

or alternatively with bis(trimethyl1,3,3 methylene-2 indoliny1)-5, having the formula:

on cn c nt cn CH III; I)

or again with the diiodide ot' bis(tetramethyl-l.2,3,3 indolinium)-5 of the formula:

The compounds I and III can be considered as dimethylene compounds for they can react respectively in the forms:

:ou and =c112 CH3 N The synthesis of these compounds has been described in the French patent application by the assignee of the present applicant, entitled Novel Substitution Compounds of Bis-(Benzothiazolyl) and Method of Preparing These Novel Compounds," No. 19,800, filed June 8, 1965 and in the French patent application entitled Novel Compounds of Bis-(Alcoylidene-Z-Indilinyl) and Method of Preparing These Compounds," No. 19,799, filed June 8, 1965.

As concerns the monohydroxy monoaldehydes to be reacted with the nitrogenous dimethylene compounds by the process of this invention, it is preferable to choose derivatives of salicylic aldehyde or of hydroxynaphthal dehydes such as, for example: nitro-S-salicylaldehyde (IV), methoxy-3-nitro-5-salicyladehyde (V), or hydroxy- 2-nitro-6-naphthaldehyde (VI).

Below are given by way of example the characteristics of various photochromic substances obtained according to this invention by condensation of the above described reactants. In all cases the condensation is effected by reacting two molecules of hydroxy aldehyde with one molecule of the dimethylene compound in methanol containing a trace of pyridine as the reaction. medium. The reaction is conducted under reflux for a period that may vary from several minutes to several hours as may be necessary. The desired photochromic substance crystallizes from the reaction mixture on cooling and is purified by recrystallization from a suitable solvent.

The following compounds have been prepared by this method:

( l Bi-(methyl-3-benzothiazoline-2-spir0-2' methyl3' nitro-6' benzo (b) pyran)-S. Condensation of (I) and (IV).

(2) Bi-(methyl-3 benzothiazoline-Z-spiro-2-methyl-3' nitro-6' methoxy-8' benzo (b) pyran)-5. Condensation of (I) and (V).

These compounds have the formula:

in which X represents H in compound 1 and OCH in compound 2.

(3) Bi-(trimethyl-l,3,3 indolin 2-spiro-2 nitro-6 benzo lb) pyranJ-S. Condensation of (II) or (III) and (IV). ('4) Bi-(trimethyl-l,3,3 indolin 2-spiro-2' nitro-6' methoxy-B' benzo b) pyran)-5. Condensation of (II) or (III) with (V).

These compounds have the formula:

CH3 Cll;

X till,

6 in which X represents H in compound 3 and OCH in (C) Utilization compound 4.

The photochromic dispiropyran compounds of this in- [5) Bi-(trimethyl-l,3,3 indolin 2-spiro-2' nitro-7' naphvention can b utili e zed either dlssolved in a solvent or in 1 pyramd Condensatlon of (H) or '(III) a semi-rigid medium such, for example, as a varnish or a sheet of plastic; the plastic sheet may be protected on This compound has the formula: both sides by sheets of glass to form triplex assemblies.

CH CH CH CH These substances have no definite melting point but decompose before melting.

Microanalysis and determination of nuclear magnetic resonance confirm the structure of these products shown above. Such assemblies may, for example, be used in sun glasses EXAMPLES for protection against solar radiation and glare.

Also a sheet of polyvinyl butyral incorporating com- (A) Examples of photochromlsm m Solunon pound N0. 5 as described under (B) above can be placed One-tenth P toluene Solutions are P p of between two square plates of glass about 2 mm. thick the b -d numbffled Compounds- These S01l1- and 20 cm. on each edge and the assembly heated to 120 tions are irradiated at the indicated temperatures for 10 and pressed h resulting triple plate ft cooling Seconds Wlth a yp SP.500 l h1l1p s rnerc y Vapor P- has a faint yellow color. When irradiated under the con- The color before and after irradiation is noted and the ditions ib d nder (A) above, it assumes a blue lime requlfed SOIUUPIIS t0 l'egaln Orlglnal color which it loses in about 30 seconds after irradiation color after radiation is terrnmated. The results are sumis terminated marlled the followlng table: As many apparently widely different embodiments of TABLE I the present invention may be made without departing Tempem from the spirit and scope thereof, it is to be understood Comture of Color Time required that the invention is not limited to the specific embodipounds trradiato regain ments tested tion, C. Before After original color t What is claimed 1s: i3 3 333 31111: 2332582. 40 Acompound having the formula 22 .....do Blue 30 seconds. 22 .do Blue-green lminute. O Yellowgreen. Blue 3seconds.

t 5 t I N N NOg; 8 --o a o -No,

CH3 \s/ \3 H3 in which X represents H or OCH 2. Bi-(methyl-3 benzothiazolelene 2-spiro-2' methyl 3' nitro-6 benzo (b) pyran)-5 having the formula:

CH OH 1 QR O O i l CH3 CH3 (B) Photochromism in a semi-rigid medium 3. B (methyl-3-benzothiozoline-Z-Spiro-2 methyl-3 A Sheet of polyvinyl butyral about 05 mm. thick r1utro-6-benzo (b) pyran)-5 having the formula of claim plasticized with butyl sebacate is soaked for 3 to 5 minutes in benzene solution containing 5 percent butyl sebacate and 5 percent of the compound to be tested. The sheet is withdrawn and the benzene removed by evaporation.

4. Bi (methyl 3-benzothiozoline-2-spiro-2'-methyl-3'- nitro-6-methoxy-8-benz0 (b) pyran)-5 having the formula of claim 1.

The sheets are then irradiated as described in (A), but References Cited at room temperature, with the following results:

TABLE II FOREIGN PATENTS C0101 gr ig Great Britain Compounds tested Before After o igii i l color ALEX MAZEL, Primary Examiner R. J. GALLAGHER, Assistant Examiner US. Cl. X.R. 

